Respirators can include a full face mask body or a half mask body or a body element of a Positive Air Pressure Respirator (PAPR). One or more filter cartridges can be attached to these respirators. Air is drawn through the filter cartridge by a negative pressure generated by either a wearer of the masks or by a blower in the PAPR. This air passes through the filter medium and then enters the mask body interior where the filtered air is then inhaled by the respirator user.
Many techniques have been used to attach filter cartridges to respirators. One technique has the filter element disposed in a threaded cartridge that is attached to a corresponding threaded fitting on the body of the respirator. Filter cartridges can possess helical or advancing spiral threads that mate with a tapped collar or socket that receives the threaded portion of the filter cartridge. Rotating the filter cartridge in an appropriate direction allows the cartridge to be attached to or removed from the respirator. A resilient, deformable gas can be used to ensure an airtight fit to the respirator body.
In lieu of threads, a bayonet type closure has been used to attach a filter cartridge to a respirator. The bayonet type connector inserts into a complementary connector portion of a mask body and a filter cartridge may be rotated to engage tabs until the tabs engage the ends of the corresponding slots, providing a positive rotational stop point. This configuration provides for automatic alignment and orientating air filter cartridges relative to the respirator.